/Engine/Source/Runtime/Engine/Classes/Sound/SampleBufferIO.h
This kicks off an operation to write InSampleBuffer to SoundWaveToSaveTo. If InSoundWave is not nullptr, the audio will be written directly into Returns true on a successful start, false otherwise.
bool BeginGeneratingSoundWaveFromBuffer ( const [TSampleBuffer](API\Runtime\SignalProcessing\TSampleBuffer)<> & InSampleBuffer, [USoundWave](API\Runtime\Engine\Sound\USoundWave) * InSoundWave, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void(const [USoundWave](API\Runtime\Engine\Sound\USoundWave) *)> OnSuccess )